Compositions used for fine polishing applications generally are relatively old and well-known, such as the oil soluble pastes, oils and waxes. Some compositions, particularly those useful in the dental field, employ a humectant such as glycerine, polyglycols and other known humectants with water to form a liquid vehicle. Gelling agents are also employed to provide thickness and include natural and synthetic gums and gum-like materials. It is also known that such compositions should include known preservatives to reduce bacterial attack of the composition and provide extended shelf life.
In dental polishing compositions, such as disclosed in prior U.S. Pat. Nos. 4,702,905; 4,528,180, 4,705,680 and 4,814,160, combinations of such ingredients are disclosed and are directed to dental creams, pastes and gels which incorporate the well-known cleaning or polishing components such as water-insoluble alkaline earth metal salts or similar agents.
These polishing compositions are useful and satisfactory for manual brushing of teeth. However, they are not satisfactory for polishing applications wherein rotary applicators are employed to obtain very fine, highly reflective mirror-like surfaces because of the type of abrasive incorporated therein. Diamond or other equivalent hard abrasives are typically necessary to accomplish a higher degree of polishing as opposed to mere cleaning of such surfaces to provide a smooth, mirror-like finish.
Presently available dental diamond polishing compositions incorporate a carrier vehicle for the diamond particles which appear to have very similar physical properties to the typical manual brushing compositions forming a creamy mass, gel or paste. Such diamond polishing compositions exhibit less than wholly satisfactory physical properties related to adherence to the applicators and/or the tooth surface during use and the ability to retain a relatively viscous character during polishing.
To obtain the desired smooth, mirror-like finish, in an acceptable manner requires using rotating applicators which may generate high shear forces and significantly increased temperatures. Under these rigorous conditions, a significant amount of the prior art compositions tend to be spun off during use. Such spin off or spattering is due to one or a combination of the following deficiencies; the intrinsic lack of sufficient adherence to the applicator or the work surface; a significant decrease in apparent viscosity due to friction caused increase in temperature which appears to be a form of melting; or a decrease in viscosity due to shear forces generated during use. This decrease in viscosity due to shear forces is common to prior art gels or pastes incorporating unidentified gums and gum-like materials and is a psuedoplastic or thixotropic flow property.
The loss of the composition by spinning off during use represents inefficient use of the abrasive particles dispersed in the carrier. The lack of sufficient adherence of the composition to the applicator and the work surface being polished also tends to diminish the effectiveness of the polishing action upon the work surface. Attempts to overcome such deficiencies in prior art polishing compositions included overloading of the composition with the abrasive agent. This is particularly uneconomical when the more expensive abrasive materials are employed and does not always yield the intended result.
Additionally, spin off of the composition during use is distracting and excessive spattering of the composition, particularly in dental "chairside" applications, is inconvenient and generally undesirable to the user and the patient.
While many presently available "diamond polishing and glazing" formulations have a consistency which permits the product to be dispensed from a syringe-type package or a squeeze tube, at least one is packaged in a semi-hard paste form somewhat like conventional shoe polish or the like.
Those skilled in this art have failed to develop a carrier agent possessing improved physical properties related to providing more efficient and effective use of the abrasive which is also convenient to manufacture, package or provide and use.
There is a need for an abrasive polishing composition having an improved balance of physical properties wherein the vehicle carrying the abrasive adheres well to the applicator and to the work surface, as well as to itself, and also possesses Newtonian or near Newtonian flow characteristics wherein viscosity is not significantly reduced by shear forces. Further the polishing composition should resist a decrease in viscosity due to the build up of heat during typical applications which can significantly reduce adherence of the composition to the applicator and work surface.